Eccentric inventor Wallace has created a device that transports him out of his bed, dresses him, and prepares his breakfast. One morning, however, his machine plops him in the 'wrong trousers,' a pair of mechanizd pants, which take him on a wild ride. Meanwhile, the domestic bliss of Wallace and his faithful dog, Gromit, is shattered when a mysterious penguin leases a room in their home. Is the penguin that Wallace has taken into their household a criminal mastermind or is Gromit just jealous of the attention Wallace has been lavishing on their new boarder? The answer is revealed in a thrilling climax that raises the bar for action in the medium of stop-motion animation.